During cooking of foods on a hot surface the food often sticks to the surface. Cooking fats are employed to coat the surface as an aid in eliminating such sticking. Two performance problems of currently available cooking fats are the development of a dark brown color and development of off-flavors if the fat is held too long on the heated surface. These are caused by the presence of lecithin which is commonly added to cooking fats as an anti-sticking agent. Lecithin aids in decreasing food sticking but the amount which can be used in the cooking fat is limited due to the color development and off-flavor development. Fats containing a higher than normal level of lecithin to enhance the anti-sticking properties darken and develop off flavors more quickly.
Despite its disadvantages, lecithin is widely used as an anti-sticking agent in cooking fats. For example, see the following patents disclosing fat-based cookware surface sprays containing lecithin as an anti-sticking agent: U.S. Pat. No. 3,896,975 of Follmer, issued July 29, 1975; U.S. Pat. No. 4,142,003 of Sejpal, issued Feb. 27, 1979; U.S. Pat. No. 4,155,770 of Doumani, issued May 22, 1979; U.S. Pat. No. 4,163,676 of Konigsbacker, issued Aug. 7, 1979; and U.S. Pat. No. 4,188,412 of Sejpal, issued Feb. 12, 1980.
Several fat or oil additives are known for inhibiting darkening of phospholipids such as lecithin upon heating. These additives are primarily acidic or weakly basic compounds such as amino acid salts, carboxylic acids and derivatives, or salts of carbonates or bicarbonates. Inhibition of discoloration of phospholipids in fatty oils during heating can be achieved by the addition to the oil of a mixture of an acidic amino acid salt and a basic amino acid salt chosen from salts of arginine and glutamic acids, lysine and glutamic acids, or lysine and aspartic acid. In addition, sodium glutaminate, acidic anhydride, or alkali metal acetate can be employed.
Pretreatment of lecithin to prevent thermal browning in heated fat compositions is taught by Japan Pat. No. 54,400, issued Apr. 21, 1980. The pretreatment comprises heating the lecithin in an inert atmosphere either alone or diluted with a fat at 150.degree. C. to 230.degree. C. (302.degree. F. to 446.degree. F.) for 5 minutes to 1 hour.
Japan Pat. No. 91,910, issued Aug. 12, 1978, discloses the stabilization of vegetable oil fatty acid monoglyceride quality by the addition of 0.001 to 0.1% by weight of disodium phosphate, trisodium phosphate, dipotassium phosphate, and/or tripotassium phosphate. The oxidation of carotene and tocopherols present in slight amounts is depressed to prevent coloration. Soybean, palm, cottonseed and coconut oil are specified as examples of suitable vegetable oils. The phosphates are added with stirring as an aqueous solution to the oil heated to 80.degree. to 100.degree. C. Solvents such as propylene glycol, sorbitol, or glycerin, are employed to assure uniformity of the mixture.
U.S. Pat. No. 3,355,302 of Purves et al., issued Nov. 28, 1967, discloses a plastic shortening suitable for frying and baking containing 0.2% to 1.0% by weight of a C.sub.12 to C.sub.22 fatty acid monoester of polyoxyethylene sorbitan containing an average of about 20 oxyethylene units per molecule. The fatty acid monoester is preferably acid treated and/or the shortening contains about 0.01% to 0.25% by weight of an oil-insoluble water-soluble salt of phosphoric acid. Suitable salts include: sodium metaphosphate; sodium phosphate, dibasic, hexahydrate; tetrapotassium pyrophosphate, anhydrous; tetrasodium pyrophosphate, decahydrate; sodium phosphate tribasic; sodium phosphate, monobasic; sodium glycerophosphate; sodium phosphate, dibasic, anhydrous; Graham's salt; and sodium hexametaphosphate having an average of 14 metaphosphate monomer units per molecule. The salts of phosphoric acid are employed specifically to reduce spatter and to aid in improving temperature recoverability of the shortening during frying.
These references disclose fat and shortening compositions containing phosphate salts as an anti-spattering agent and to suppress color development, but not that phosphate salts are effective as an anti-sticking agent and can be used as a substitute for lecithin. Eliminating the use of lecithin as a component of cooking fat compositions eliminates the resulting problems of thermal browning and off-flavor development when the fat is used in frying or grilling.
Accordingly, it is an object of the present invention to provide a novel anti-sticking agent for use in cooking fats.
It is a further object of the present invention to provide fat compositions having effective anti-sticking properties in the absence of lecithin.
It is a further object of the present invention to provide fat compositions having effective anti-sticking properties in the presence of reduced levels of lecithin.
It is a further object of the present invention to provide fat compositions containing an anti-sticking agent with improved color and flavor during use.
It is a further object of the present invention to provide a novel process for reducing sticking of food during cooking.
These and other objects of the invention will be evident from the following disclosure.